Secret Project - Update 1

Here's a very early look at another nerd project I've started working on.  No hints, I'll leave it to your imagination as to what I'm up to.  More to follow in the coming weeks and months.

Air Conditioner Power

In writing yesterday about evaluating the cost effectiveness of our fancy whole-house fan I mentioned that I only had a way of measuring how much air-conditioner run time was saved by using the fan, not the actual dollars and cents difference.  If I knew how much power the air-conditioner used I could make a rough guess on reduction in the energy bill due to the fan use.

Today, I found a way to measure the power and can now fill-in that gap. The number: ~4kW. (You have no idea how long I've wanted to know this number. This made my day.)

This is an astoundingly high number but I don't know how it compares to other air conditioners. Obviously power consumption depends on size; the window units are rated between 1 and 1.5kW. Our air conditioner is old and I bet its efficiency is not that great but I have so little documentation on it that I can't compare it to other more modern units of equivalent size.  Maybe that will be my next bit of research.

Now for some math: Even with a power bill, it can be hard to figure out the $/kWh we all pay.  Let's assume somewhere around $0.1/kWh, a ballpark number that makes the math easy. Using  $0.1/KWh and looking back over this summer's usage of ~8/day, the energy cost just for cooling is $3.20/day; 30 days in a month brings the total to $96/month.

As far as the cost effectiveness of the fan goes, well, there's still a few more complications.  The easiest one to address is the energy consumption of the fan itself.  Looking this up in the manual shows the fan is rated at 292W on high (which we most often use) .  This is a 1:13 energy consumption ratio between the fan and the air-conditioner.  For ballpark analysis purposes, we could probably just consider the energy consumption of the fan as negligible.  Its a bit of a stretch but my work so far has been just as imprecise and I can live with this.

The second issue is very much related to what I discussed yesterday: how many hours over the course of the summer am I using the fan when I would normally be using the air-conditioner?  The results of the experiment I wrote about yesterday show a 25% reduction (using awful experimental techniques) in air-conditioner usage when I use the fan.  Many days of the summer, though,  I can't use the fan at all as the overnight low is still above the indoor temperature.  If I get really committed I might go back through my temperature data and try to make some kind of estimate; that's more work that I want to mess with right now.  For tonight, I'm once again going to table this.

Effectiveness of Whole-House Fan

As I've written before, two years ago we installed a whole-house fan in an attempt to make better use of the sometimes-colder outdoor air to cool the inside of our house.  The fan has been great but I've been wondering if it was a good economical choice.  Would we have been better off just spending the money on air conditioning rather than this fancy fan?

To answer this question I would need to compare how long the air conditioner runs on days when we use it versus days when we don't.  Oh, and the days would have to be identical. Since I don't control the weather, doing a direct comparison is pretty much not going to happen.  The next best strategy is to find days with similar weather, use the fan one day and not the other, and do this a bunch of times to average out all the actual differences in the weather.  This is a better strategy but has two problems:

1. The decision on whether to use the fan or not must be made without knowing the upcoming weather for the day.  Obviously weather forecasts solve this somewhat but it may be hard to decide if the predicted weather for the day is equal enough to the weather in some arbitrary previous day (where I've already collected your data) to make the comparison worthwhile.
2. By definition, there will be days when I could use the fan but choose not to (so I can collect data for the air-conditioner-only case).  I bought this big fancy fan and I don't get to use it? And I'm doing this so that I somewhat scientifically determine if using this big fancy fan I already bought is doing what it should?  

In light of these two complications it became obvious to me that to do this experiment well requires more commitment to good scientific principles than I can bear right now.  Instead, I did the smallest experiment possible: two days that are vaguely similar in weather one using the fan and one not, measuring the amount of time the air conditioner runs on each day.

This graph shows the outdoor temperature on the two days I ran this experiment. The days are far from identical but do have a similar daytime highs and general temperature trends throughout the day.

The measured air-conditioner runs times are as follows: fan + AC: 3.8 hrs, AC only: 5.1 hrs.  That's a time savings of 24% when running only the fan.  The real question is how much money this saves me and for that I need to know how much energy my air-conditioner uses.  I don't have a way of measuring that at the moment but I've got one in the works. For now I'm going to have to be satisfied with run-time.

UPDATE: I've got a partial follow-up where I get an estimate of the air conditioners power consumption.

Memorization

At the beginning of the summer one of the pastor's of my church challenged the congregation as a whole to memorize a particular book of the Bible, James 1.  Memorization is not my strong suit but I am not one to turn down a challenge so I dug in.  Well, at least for the first month or so during which time I got about half way there. During a sleepless night last night a thought came to me: my Mac can convert text into speech and I bet those spoken words could be saved as an audio file.

It can.

Here's the workflow to download if you feel frightened by the idea of building it yourself in Automator.  The file needs to be placed in your ~/Library/Services/ folder, that is, the Library found in your home directory. (If you want to make it available for all users of your computer, just place it in the global library folder /Library/Services/).  If you don't have a Services folder in your library just create one and drop it in.

To use the service just highlight the desired text, go to the menu of that application, select "Services" and then "Text to AAC".  The workflow will create an AAC audio file out of that text and save it in your iTunes folder as a song called "Text to AAC Output". Not only is this a neato demonstration of a built in feature on all Macs, but it has been actually useful in helping me with my memorization.

Home Power Monitor - Arduino ADC Speed

An important part of my home power monitor is the ability to measure the instantaneous power for a given circuit; this will allow me to calculate other important nerdy things like the power factor and reactive power.  This approach requires frequent sampling of the voltage and current waveforms so that the average power over many 60Hz cycles can be found.  There are two important points in making this work well:

• The voltage and current should be measured (ideally) simultaneously so that the power at that specific point in time can be determined.
• The rate at which new voltage and current measurements are made needs to be high enough that the accumulated samples form an accurate representation of the source waveform.  This is especially true if the current waveform has transients and nonlinearities (due to non-linear loads caused by power electronics).

Both of these factors are highly dependent on the speed of the analog-to-digital converter (ADC).  Assuming that multiple-channel simultaneous ADCs are not being used (which is the case for my system), separation in time between the voltage and current measurements will be entirely a function of the conversion time.  The measurement of the current can't start until the measurement of the voltage is complete.  Similarly, the rate at which the 60Hz voltage and current waveforms can be sampled is determined by how long it takes one voltage-current measurement pair to be made.

For the sake of simplicity, this prototype system I'm building now is going to use the Arduino's on-board ADC.  This ADC has a built-in multiplexer which has a reputation for not being very fast but since I am planning on using an external multiplexer to accommodate all the power circuits I want to measure (the Arduino can only mux in 8 channels, my plan calls for 13-16), I can get away with only using a single channel for the on-board ADC. 

The question that remains, then, is how fast the on-board ADC can do a conversion.  My prowling of the internet found some very experienced people who found a way to adjust the clock that the ADC uses when converting.  The ADC clock runs at a scaled down rate (prescaler) of the main system clock and the scaling rate can be changed programmatically.  A part of the documentation for the microprocessor used in my Arduino states:

The ADC accuracy also depends on the ADC clock. The recommended maximum ADC clock frequency is limited by the internal DAC in the conversion circuitry. For optimum performance, the ADC clock should not exceed 200 kHz. However, frequencies up to 1 MHz do not reduce the ADC resolution significantly.

Operating the ADC with frequencies greater than 1 MHz is not characterized.

Ignoring the actual results from the conversion, I decided to characterize the time it takes for the ADC to complete a given number of conversions.  The results from this test are below showing the conversion time for a varying number of conversions.  The last column is the difference in the 1 million conversions time as compared to the previous prescaler value.

Prescaler Value     1k conv.   10k conv.   100k conv.   1M conv.   Difference
2                     7.52us     7.43us      7.42us       7.42us    -
4                     9.53us     9.32us      9.30us       9.30us    1.88us
8                    12.78us    12.57us     12.55us      12.55us    3.25us
16                   19.15us    19.04us     19.04us      19.03us    6.48us
32                   32.19us    32.02us     32.00us      32.00us   13.00us
64                   60.28us    60.24us     60.24us      60.24us   28.24us
128                 112.24us   112.02us    112.00us     112.00us   51.76us


There are two reasons to feel confident in this data:

1. The conversion time is reasonably consistent across the various number of conversions.  There is not a dramatic difference in the calculated conversion time when the loop contained 1 thousand conversion and 1 million conversions.
2. The difference in conversion times scales very nearly linearly with the prescaler value.

Based on these results and the documentation's note that the ADC should operate reasonably well up to 1 MHz, I am planning on setting the prescaler to 16 giving me that 1 MHz conversion rate.  Doing the math: 16 channels at a conversion time of 19us per channel gives me a total of 304us to sample all channels.  With a 60 Hz waveform this allows 54 samples across all channels in one cycle.  This is maximum conversion rate I should expect; the test above does nothing with the conversion results except store them.  The arithmetic I need to do will slow the process down; characterizing that will be another test I'll have to do once the hardware is complete and I have a fuller start on the hardware.

Home Power System - Hardware Build - Part 2

Here's the latest developments in the home power system monitor:

The black rails down the side are the connectors for the current sensor connector modules. Yes, that makes it a connector for a connector. This is what happens when you buy connectors that you can't solder directly to the board. I've also decided to provide connectors for (and thus modulize) the analog mux I'm going to be using to read all these signals into a signal ADC port on the Arduino, the Arduino itself, and the radio I'll be using to send the information on to a computer for reporting.

The two sockets towards the top are the amplification modules for the current sensors. Each socket will hold two MCP6002 op-amp DIPs giving me a total of four channels per socket. I would have used the correct sized socket (one DIP per socket) but I forgot to order more and my supply here at home is almost gone.

I've completed four channels so far with four more to go before I get done creating channels for all of the circuits in my house that use both sides of the split-phase wiring. This makes eight current sensor channels to read four appliances here at home: mains, air-conditioner, oven, and clothes dryer. For now I'm only going to add three more channels (for a nice, even 11 channels total): refrigerator, entertainment center, and downstairs utilities like a chest freezer and clothes washer. Assuming this all works fine, I have room for three more channels in my current design.

Home Power System - Radio Assembly

Each one of those green things is a radio capable of transmitting and receiving data when hooked up to an Arduino.  You'll notice the there are actually two boards soldered together for each module.  My good friend Keith did the layout and legwork in getting the "motherboard" PCBs produced and last night hand-soldered all the components except the radio itself. Note the impossibly small size of the chip on the backside of the board (labelled "TXB0108").  Did I mention that Keith really enjoys doing detailed work like this?  I picked the boards up from him this afternoon and soldered on the radio "daughterboards" this evening.  My work is the messier of the two; forgive me, Keith.

The radios are quite impressive little beasts that provide a large amount of functionality in a very small package. For $7 I got everything I'll need to transmit my power measurements from one Arduino up to the Arduino I'm using right now for my home temperature monitor. I'll be able to use those existing scripts and data presentation methods to generate all the graphs I'll need. There is a lot of information out there on using this radio and I am hoping/expecting it won't be too difficult to get working. The only thing missing now from these modules is the antenna which will simply be a few-foot-long piece of wire.


The tiny chip on the back is a relatively expensive level shifter to convert my +5VDC Arduino signals down to a +3.3VDC that the radio is expecting. Other's have done this level shifting with resistors on signals headed to the radio (and nothing for the signals coming from). This seems to work just fine but technically such a plan doesn't quite meet Vih/Voh requirements; there is a small chance that some batch of chips will barely meet their specs but not work in this application. To avoid this possibility (and try out a new chip), Keith and I decided to go with the level-shifter and see how it works. I probably won't be testing the radios for a while as I'm focussing on getting the other hardware assembled.

Home Power System - Hardware Build - Part 1

For the past few months, in my voluminous spare time, I've been working on developing a system similar to my home temperature monitor that would monitor and record electrical power consumption.  The system will  measure the total power consumption of the house as well as that of a select few circuits (air-conditioner, oven, microwave, ...). The design has been almost entirely on paper until yesterday, when I started soldering and testing the first pieces of the design.  Below is what I've accomplished so far:

The two blue blocks on the left and right is where the two phases will be plugged in and the big white, brown and yellow blocks are transformers that will change the voltage from 120VAC (RMS) to 8VAC (RMS).  Most of the components along the top use one of the outputs from the transformer to make a +5VDC power supply; there is also a precision +2.5VDC reference (and capacitor) at the very left of the row of components.  Below that row of components are two op-amps (my new favorites, the MCP6002): one buffers the precision reference and the other (not quite complete) is used to scaling down the voltage supply from each phase to be sampled and used in power calculation.

I've been testing as I've built and so far everything works great.  I learned that the precision reference I'm using (MCP1525) REQUIRES a capacitor on the output and that its important to take your time and get the wires soldered in the right spot.  The later is a bit tricky when you're constantly laying the parts out on top but having the solder the connections on the underside. I'm considering this a prototype version and, assuming it works well, may at some point turn this into a more professional design by making a PCB.

For those interested in the theory, in broad strokes, here is how I plan on measuring power consumption. I am interested in measuring the full complex power which means I need a way of determining the phase difference between the voltage and the current. After some consideration, I decided the best way to go is to sample the voltage and current waveforms directly and calculate the power as the multi-period average of the product of those two.  This is the most general (and hardly ever used) method for calculating power and it allows me to measure the non-sinusoidal waveforms that power electronics (computers, TVs, ...) generate.  Using this technique also allows me to calculate RMS voltage and current which can be used to calculate the apparent power and from there the reactive power and power factor.

Using the general approach is powerful because it enables all these other measurements but it has its own complications.  Since this is truly an AC system, half of the waveform is positive and the other half is negative and is therefore outside the voltage range of the Arduino's ADC.  To make the system work, I'm having to do a bit of signal conditioning to shift all the AC waveforms so that they are centered around +2.5VDC and and adjust the amplitude of each signal so that its maximum voltage swing is 5Vpk-pk. (This is the reason for the +2.5VDC precision reference; it provides a stable elevated "ground" point for my signal conditioning).

Thankfully, the same mechanisms I'm using to isolate this board from the high voltages and currents in a home power system also serve to allow my reference point to be moved up from ground to +2.5VDC: transformers.  All the voltages and currents are measured through transformers which removes the negative side of the signal from the true ground reference and allows me to assigned this signal a reference of my choice. One of the op-amp on the board above handles the amplitude adjustment and scales the signal down so that it fits in the 0VDC-5VDC range.

Panoramas

I just stumbled upon a free photo stitcher called Hugin and have been using it to redo the panoramas I have taken over the years.  I previously used Photoshop Elements 3 (which must be around 10 years old) and I have not been very impressed with the results.  Hugin has been great, though.  The software is quite complex and there are settings and options far beyond my comprehension.  Thankfully, there is a three-step bozo mode that by-passes most of the mess and seems to just work, most of the time.  The results are great and I am enjoying being able to breathe new life into these photos.  

Pike's Peak (part-way up)

Pike's peak (almost at the peak).

Kuaui, Hawaii

Kuaui, Hawaii

View of the refineries on the north side of Baton Rouge

Garden of the Gods, near Colorado Springs

MagicJack Tech Support

This is one for the nerds.  If you've ever been frustrated by technical support that seems to know less than you, you're going to be able to relate.  I just ended my technical support chat with MagicJack, an internet phone company.  The support chat ended when I was informed the chat had ended; this is prior to finishing our trouble-shooting.  Even though I think they were headed down the wrong path I learned what I needed to know and managed to make the changes on my own.

Please wait for a site operator to respond.

You are now chatting with 'Marianne'

Your Issue ID for this chat is XXXXXXXXXXXX

Marianne: Hello, how may I help you?

Trevor: My USB Magicjack is constantly giving me the "Error 1 - No network connection message" even when I know I have an internet connection.

Marianne: May I have your Magicjack phone number please.

Trevor: 316-XXX-XXXX

Marianne: Please wait while I check that for you

Marianne: May i know  what device do  you  have a problem  with? since   I have check it here  you have 1  mj plus  and 1 old  mj device  here  in your account

Trevor: MJ Plus.

Marianne: May I know where did you used to plugged in your mj plus device in the computer or to the wall?

Trevor: Not plugged into my computer.

Trevor: Its plugged directly into the wall for power and also to the internet.

(I was trying to keep things simple at this point and answer the question the support person was trying to ask. The plug "to the wall" doesn't really describe the device well.)

Marianne: May i know if  you  have a  router there?

Trevor: Yes, I have a router

Marianne: May i know the   router  brand  model   that you are using please?

Trevor: Router is an Apple Airport Extreme.

Marianne: I   need the  exact  model  please

Trevor: The device identifies itself as an "Airport Extreme 802.11n (2nd generation)"

Marianne: One moment please...

Marianne: This issue is fixable, please allow me to guide you, so we can trouble shoot on your computer

Marianne: Please plug in your magicjack plus   device now to your computer.

Trevor: OK

Marianne: Please click the link to download and run the magicJack upgrade:

Marianne: http://upgrades.magicjack.com/upgrade/magicJackSetup.dmg

Marianne: Please inform me if you see dial pad after you run the upgrade link.

(This was helpful.  I had forgot to try a firmware update and having the link handy is great.)

Trevor: Running the installer now.

Marianne: Okay

Trevor: I see the dialpad now.

Marianne: Please  check if  you see  “   stock symbol Call’ there?

(I saw something that said Stock Symbol:Call" so I answered "yes".  I think this was the correct answer.)

Trevor: Yes, I do.

(At this point I plugged in a phone and tried to make a test call to see if things were working.  They were.  The support person doesn't seem to want to check this right now so I keep playing along.)

Marianne: • Please click the MENU on your SoftPhone dial pad and choose "VOLUME/HEADSET CONTROL." then tell me if you can switch between telephone or headset/other

Trevor: Yes, I can check either of the two boxes ("Telephone" or "Headset/Other") and the settings in the window change.

Marianne: Please  set it to telephone there  

Trevor: Done

(I don't know how this is going to fix my the connect problems but, oh well.)

Marianne: . Please click Apple menu at the top-Left corner of the screen and choose"System Preferences." Then open "Sharing" Icon.

Trevor: Done

Marianne: The first section that appears is the "Services" settings, Please check the entries that says Internet Sharing, Web Sharing, Windows Sharing, File Sharing and XGrid Sharing.. And click Start if you have a start button...

Trevor: Done

(This is crazy.  None of these services are necessary for this device to work properly.  This is like saying you need to open your windows, tilt the rearview mirror all the way down, and sit in the passenger seat when you start your car.  I know this because my Magicjack used to work just fine even when it was never plugged into my computer.  By starting up all these services I am (marginally) decreasing the security of my computer.  This is time-wasting, unnecessary, and slightly scary.)

Trevor: How will settings on my computer affect the MJ when it is not going to be plugged into my computer during normal use?

(Yeah, so this is the my big complaint.  My Magicjack is the kind the plugs directly into the router rather than into a computer.  We established this at the beginning of the chat.  It doesn't seem like I should have to make any changes to my computer to get the device to work properly. )

Marianne: We are doing  fixes  now. Please    just  follow the  steps   I gave to  you  

("Fixes". Got it.  I guess I'm just going to undo everything after this chat.)

Trevor: OK

Marianne: 5. Please click on the "Firewall" tab.

Marianne: 6. Please check if it says "Firewall Off" or "Firewall On".

Marianne: 7. If it says "Firewall On" please click on the button "Stop"

Trevor: I see no "Firewall" tab in the Sharing Preferences.

(The reason I don't have a "Firewall" tab is because I'm not running Windows.  Somehow the support person copied and pasted the wrong script into the chat.  Didn't even bother to take the step numbers out of the document she's looking at.)

Marianne: Okay..

Marianne: Please click Apple menu at the top-right corner of the screen and choose "System Preferen

Marianne: I  mean for  "System Preferences."

Trevor: Done

Marianne: Please open Network then click on your active Network Connection (Example: airport, Ethernet) and tell me the IP address

Trevor: IP is 10.0.1.107

(Uhmm, I don't think the IP address for my computer is going to fix this because, as I've mentioned, the Magicjack is not normally plugged into my computer. This is fixing a problem that doesn't exist.)

Marianne: . Please open up the Finder on your Mac task Bar and click theApplications button near the left of the page.

Trevor: Done

Marianne: Please click the Utilities button near the right of the page and click theAirPort Admin Utility button near the right of the page.

Trevor: Done

Marianne: Please Select Apple Base Station from the Select Base Station list. >>> Click the Port Mapping button near the top of the page. >>> Then click the Add button near the right of the page.

Trevor: Done

(These instructions are awful but I have had enough experience with my router that I knew what needed to be done. I pity the less educated who must try to decipher these obtuse and misleading instructions.)

Marianne: Please type in 5060 on both Public and Private Ports, The type 10.0.1.107 _(use the IP address) for Private Address and click OK

Trevor: Done.

Marianne: Please click the Add button. again and type in 5070 on both Public and Private Ports, The type 10.0.1.107  (use the IP address for Private Address and click OK

Trevor: Done

Marianne: When you're finished, please click Update near the bottom of the screen to save your changes.

Trevor: Done

Marianne: Please restart your Magicjack device. Just unplug then replug it after 2min

Trevor: Waiting 2 min...

(2 minutes!  I have no idea why we would need to wait that long.)

Marianne: Okay

THIS CHAT HAS ENDED.

So, from this chat, I learned I needed to update the firmware on the MagicJack and what ports I needed to set up to forward to the MagicJack when its plugged into my router.  No explanation as to why it stopped working a few days ago.  For now, we're back up and running.

Oh, and in case you're wondering, I don't recommend Magicjack.  Its cheap but you get what you pay for.  Since we hardly use this phone, its OK that it seems to hardly ever work.  I'm probably not going to renew after the first year.

Baton Rouge Plantations

My wife was very interested in visiting plantation during our trip and even though we went to three, I think she would have liked to see many more. She and her family are very history-oriented and the continued existence of these old buildings over a century old have great appeal.

Though I do not share her great interest, I did have some mixed feelings about visiting these sites. Not growing up in the South, this was my first direct contact with the pre-Civil War era and, arguably, the root of that war, the in humanity that was so tied up in it: slavery.  I grew up far removed from the troubles our nation's legacy of slavery have and continue to create; I didn't grow up in the South and this is not a part of my cultural identity.  I do appreciate, though, that these plantations can easily be seen as a symbol of that dark mark on our history and it seems awkward to make them historical sites and museums, tourist destinations.  By the same token, they are historical sites, they are significant artifacts of a former time.  Removing or ignoring the buildings serves little purpose and may not be beneficial; ignoring the past gets us nowhere.

I'm embarrassed.  Even though I had nothing to do with it, I'm embarrassed that this is a part of our history and I wish it had never happened. Its like being reminded of some foolish choice made in adolescence or dealing with that drunk uncle at your wedding who has lost all inhibition.  Its true, it happened, it can't be denied; I just want it not to be so.

And make of this what you will: during our time touring these three plantations, I only saw one African-American and she was working as a tour guide.

The philosophical misgivings aside, the plantation complexes and the central homes that are its focus are truly wonderful old buildings.  As all our tour guides said, these plantations were owned by the supremely wealthy of their day.  This was not their only residence and they may or may not have been living there year round.  The United States has largely rejected the more class-based cultures that have been a strong part of Europe's past but these plantations were truly a mark of the aristocracy of that day.  The owners needed and lacked for nothing and had the finest available in all respects.  Who else pays for hand-painted wall-paper murals to be custom-made and imported from Europe?

The age of the plantations is echoed in the age of the trees.  Though not as old as many of the forests I grew up around, the branching, reaching, canonpy-ing of these centurion oaks was impressive. This kind of beauty can only come with time; there's no rushing the slow majesty that is old growth.

There is so much of these houses that exudes the wealth of their creators.  The expansive gardens, the architectural details, the size of the houses in what were very rural settings.  Its hard to imagine having so much material means that your country home could easily house multiple families.

One of the plantations we visited was unique from all the others: it was only forty years old.  All except the columns of this building had burned in the 1950s and over the 1960s the home was rebuilt to its former glory.   It is an ersatz plantation which brings with it a distinct advantage: the building has all the modern benefits of appearing to be a planation with none of the burdens of historical preservation.  The current owners live on the third floor, there are some out-buildings that are rented as a bed-and-breakfast, and receptions are frequently held on the lower two floors.  Though the house is populated with period furniture, it is all reproductions and can be used practically.  When TV or film productions need a planation home, this is the place to go as it can be entirely redecorated as needed. The owners make their entire living by providing this fake plantation for use by whomever needs it.  In my mind, this is an ingenius use of the home and grounds.

Radioactive CFL

If you have very many compact florescent light (CFL) bulbs, you may have noticed that they glow for a while after you turn them off. The above is a ten second exposure in such a situation.  I didn't expect the green color.

Bueracracy Frustration

This past week had been a week of delays for me as the bureaucracy that is Wichita State has been dominating my attention. That I even have time now to voice my complaints and frustrations when I should be busily solving the world's energy problems (at least a small subset thereof) is evidence enough.

Item 1 - New computers
I came to school on Monday to find the new computer I will be using in my simulations had arrived.  By "find" I mean "eventually find somewhere on campus" as it took about an hour to locate them and get them moved to my desk.  I spent the morning unpacking them, scrounging for a monitor that will work, and installing basic software.  By the afternoon it was time to move on from basics and get the big, expensive software I'll be using installed.  I go to the IT department to ask for the disks and find out that my work this morning has been out-of-bounds.  Only the IT department can set up computers and I needed to turn them over for processing along with the list of software I would like installed.

I feel all hope draining from my soul.  I'm ready right now to work on getting my computer up and running and am confident that if given this opportunity, I can be done by the end of the day.  The IT department, on the other hand, has many other jobs on their plates (some with higher priority than mine) and may have the job done by the end of the week.  Additionally, some of the software I would like installed is not available for general use, despite indications otherwise.  Oh, and they need me to generate a work order so they can officially take on this task.

With heavy heart I wheel the computers to the IT department, like a father watching his children being sent off to a labor camp or prison.  I might see them again, someday, and maybe they'll be better for it, but they won't be the same anymore.

Item 2 - Network access
This computer I just got is the first one I've had at my desk.  When I was clandestinely setting it up Monday morning I discovered the network port at my desk didn't work.  I submitted a work order to have the port activated and in the mean time, used  a fifty foot cable to connect to a known working port elsewhere in the lab.  Today I received an email today stating that this work order was being cancelled and I needed my supervisor or the department head to authorize the work.  My supervisor is out of town and the department head probably has better things to do than submit work orders for network ports.  We'll see when it gets done.

Item 3 - Timesheets

I don't know if something has changed recently but I also found out that this week that as a Graduate Research Assistant, I will now be required to submit a timesheet.  I felt like the protagonist from "Office Space" as I received multiple emails each from a different person informing me of this, each with slightly different instructions for completing the form.  The form needs to be printed out and signed by my supervisor who is out of town for a few weeks.  The form needs to be turned in on Friday and include the time worked on Saturday.  The form has no easy way of indicating that I have gotten very little done this week as IT has had my computer except to write in "0" hours for each day.

I'm in favor of accountability and actually appreciate the discipline of having to document the time I spend working for the school; I am being paid for this research I'm doing.  I think this paper form is not the best way of going about this.  This fall when I teach, I might be on the "supervisor" side of the form if I'm managing lab assistants.  I doubt the experience will be any better.

Baton Rouge Capitals

Baton Rouge is the capital of Louisiana and it has a fantastic capital building.  Actually it has two fantastic capital buildings and both are impressive in their own right.  The old capital is a smaller, castle-looking building that has been turned into a museum.

The interior of the building is equally impressive, very ornate, sparkly, and colorful. The main lobby area has a steel staircase winding up to the second floor which holds exhibits and a portrait gallery of former governors.  The staircase, though, gathered my attention immediately.  Because it was made of steel and felt very different than the stairs I normally tread.  It took up much less space than concrete or wood staircases which lead to a small magical feeling, like it was impossible that something so insubstantial could possible support my weight.  And stepping on the stairs had a different tactile feel; no thud of concrete or squeak of wood but a slightly springiness and vibration.  The stairs felt responsive and nimble, not monolithic.

There were several examples of stained glass wonderfully made.  The ceiling above the central staircase was all stained glass and several windows in both legislative chambers were done as well.  Both of these rooms were beautiful and we were told that they were often used for receptions.

The other capital building, the one where the politics gather to work, is an art deco tower  similar to the capital of Nebraska, at least on the outside.  In fact, it was noted in several places that the Baton Rouge has the tallest capital building in the world, Nebraska's is second.

The main lobby of the capital is a barely lit place.  It seems almost every surface is covered in dark marble, dark stained wood, or bronze.  The day we toured was a working day at the capital and there was a constant flow of professionally dressed people in and out of the building.  The lobby was busy and loud; I felt out of place as a tourist, as if I somehow was intruding or getting in the way.

At either end are the legislative chambers, equally ornate but much better lit.  The Senate was not in session but the House was very busy passing legislation.  In the twenty minutes we were there about eight bills were passed.  It was all very perfunctory, so much so that most legislatures spent most of the time talking, ignoring the proceedings, or not being present.  This didn't keep them from voting, though.   The voting used electronic devices at each representatives seat with a big display at the front of the room showing the status of each representatives vote.  On several occasions I saw representatives voting for those around them who were absent.

And there were the pages.  Most say off to the side with nothing to do, waiting to be called on and be made useful.  The only two I saw busy were those assigned to the printers on either side of the front of the chamber.  When a representative printed a document, the page delivered it.

I have no reason to believe that what I witnessed is abnormal in any way as compared to other legislative bodies in this country.  Compared to what is normally airing on CSPAN, the attendance here was quite impressive.  It seems that there is something fundamentally wrong with how our country governs itself when laws are created in such a manner, when the act of governing is given is little attention.  This is easy for me to say, though; I've never had to do what these people do.

Lastly, like Nebraska, the Capital had an observation deck at the top of the tower. The view of the area is impressive: the Mississippi river, the refineries north of town, the downtown area, the LSU stadium and arena.  And the surrounding jungle/bayou/swamp, the ever present explosion of green.

Baton Rogue Landscape

My wife and I just returned from a brief trip to visit family in Baton Rogue, Louisiana where I had my first up-close experience with the Cajun south, the swamplands and bayous that make up the low-lying Mississippi basin. Its easy to under-appreciate the rampant life that this land breeds. From insects to alligators to ancient oaks to strangling vines the whole region explodes with growing things; its probably most accurate to think of the area as a less temperate jungle. one that occasionally almost freezes in the winter.  Its easy to see why agriculture took root down here.

The Mississippi river enables all of this growth and the seasonal floods that we have mostly contained with levies still drive the ecology of the area.  The water table is always just below the surface; I have no idea how they build houses, bridges, and skyscrapers with soil that is always so saturated with water.  The water is always in the air, as well.  The humidity allows the famous Spanish moss to grow of the oak trees and caused me to sweat whenever outside, even when the temperature was not very high.

Our more structured human life is also enabled by the River.  the Mississippi is famous for the commerce it enabled and the area plantations all took advantage of it from the beginning.  We still use it today, but for more sophisticated goods like oil.  North of Baton Rogue is a large oil refinery complex that receives tankers coming in from the Gulf; I don't know if the refined product is similarly transported out the way it came in but it easily could be.

The most exotic creature I experienced was the famous alligator, living in a wildlife refuge we explored.  Most of the time all we saw of them were the famous pair of eyes, watching us watching them.  We were also luck enough to catch sight of one fully out of the water, hiding in the shade of a tree.  None of these animals were very large (by Hollywood standards) but all seemed more than capable of defending themselves from pesky photographers like me.

That same refuge had a bird sanctuary; large platforms several feet above the surface of the water to provide a place for the birds to roost and be protected from the previously mentioned predators.

More to come in the following days ...

Nerd Corner

Behold, the efforts of several months of labor: my basement nerd corner:

Due to my hobby and school projects often monopolizing our dining table, my wife and I agreed that if I could find a desk for cheap, we could rearrange things in a basement a bit and give me some space where my sprawling mess could live.  In a week or so of hunting Cragislist I found this "L" desk for $50.  The desk is an oak monster and the effort in getting it downstairs dulled my enthusiasm for the project somewhat. I got all the computer stuff re-situated and then at a much more relaxed pace re-organized the material in my old desk into the new drawers.  This evolved into a culling and scanning activity where the amount of physical paperwork I had on hand was significantly reduced.

A month or two ago I realized the utility of the desk was significantly reduced due to all of my electronic components and tools being in boxes rather than readily available.  I began a hunt for shelving options and, again, with my wife's input and guidance, found a way to construct some ugly yet functional shelves with scrap lumber we had on hand.   The result is shown on the left, resting on the desk and almost reaching the ceiling.  Another Criagslist find got me the "mailbox" shelving on top and after spending WAY TOO much on fishing tackle boxes, I was able to sort and store virtually all of my components.

The component storage taking up the top half of the shelving, I left myself some work space in the bottom half and put a shelf half way up for miscellaneous tools.  To store the rest of my tools I cut up a dowel into pegs and drilled holes everywhere I pleased, hanging tools throughout the shelving.  For lighting, I purchased a plug-in work light and screwed it into the bottom shelf.

Today I added two small finishing touches.    The blue patches on left is masking tape holding up some cheap red/green LED lighting in a very ugly manner to provide a small amount of light for the tools on the bottom shelf.  I also added some hooks to store my banana cables behind the shop light.

Having this work space has been fully wonderful and I am some thankful to my understanding and supportive wife in this.  There may come a day when we don't have the space for something like this but for now, it is a great blessing in my life.  There is enough space that projects can live on the desk and not interfere with the rest of our daily lives.  My wife gets a cleaner kitchen table and I get space to nerd out.  As they say, its a win/win.

Wichita PSERC Day 1

Yesterday was the first day of the spring 2012 PSERC conference and this year Wichita State is hosting. Unfortunately, due to the reconstruction of the student center on campus, we're hosting the conference at the newly remodeled Drury Plaza Hotel Broadview. The hotel is great but it's not the same as being on a university campus. There was a lot of interesting material covered yesterday (at least for power nerds like me) but there was one talk in particular that seemed more widely applicable; it was titled "Do We Need a 21st Century Electrical System?". The speaker's answer was a resounding "YES!" and he made a compelling case. The system we are using today is by and large over 50 years old and was built in a very piecemeal fashion with each utility around the country doing its own thing. As the system grew these utilities began to connect to each other which allowed more and more energy exchange between the utilities, helping each other during emergencies and other unexpected events. These energy exchanges soon became the daily norm these local utilities found themselves as parts of a much larger system, each controlling a small part of the system and being influenced by the choices of others, even those geographically distant. The grid when it was built was not designed with this kind of operation in mind. Energy is now routinely flowing long distances from the generators to customers and a much higher degree of coordination is needed between the utilities. More and more we are thinking of the "grid" as a single entity and a greater need for information regarding the state of the grid is becoming evident. Customers are using more and more energy and the ability to build additional transmission lines is becoming more difficult due to population growth and the lack of available land in and around urban centers. We, the power industry, are being presented with a unique opportunity. In a relatively short portion of time, much of this aging equipment will be replaced and/or upgraded; we have the possibility of largely transforming a patch-work system that has been organically grown to meet pressing needs of the moment into a system that has been designed with intentionality and foresight to handle the expected needs of the future. The hardest part of making these changes in a unified fashion is the question of coordination. Standards need to be agreed upon by all the industry members and decisions need to be made with the bigger picture in mind. This is extremely difficult to do purely from a technical standpoint, never mind the vast political complications. I don't know how this will turn out. I think we as power engineers all desperately want a better system that we have now and recognize the opportunity we have. But will we choose to sacrifice and expend effort to together to make this happen? I don't know, we'll just have to see.

Summer is Nigh

The weather is changing.  This week the overnight lows have been right around 70'F and the highs have been in the mid 80's.  We've been using our whole-house fan all week and its been keeping us cool enough but the first day for the air conditioner is just around the corner.

We had our second major thunderstorm of the season on Monday, one of the few rainy days we've had this spring.  I was able to get a few lighting pictures out of it; something I've wanted to do for a while.

On an unrelated note, I caught Ansie doing her confused head-cock on the porch yesterday afternoon.

Wichita Wildlife

As I was biking into school last week I realized that throughout my entire life in Wichita, I have lived very close to the river that flows through town.  The places I have called home, all three of them, have literally been a stone's throw from the banks of the Arkansas (locally pronounced "Are-Kansas").

This occurred to me on my ride as the path took me along the river and I startled a beaver in the water.  He quickly dove into the brown water and my view of him changed from a swimming nose to the characteristic large flat tail.  This was my second wild beaver-sighting in here in Wichita (more than I ever saw in Oregon, the proverbial Beaver State); the first was shortly after I got married.  I was taking out the trash at night and in glancing down the street I saw a very large, short-legged animal duck into the storm drain. By "large" I mean larger than most dogs, maybe the weight (but not height) of a St. Bernard.  Again, the tail gave him away; definitely a beaver.

Last week on a bike ride along a storm-water canal running right through the center of the city my wife and I saw a fox running through the weeds and grass growing along the bottom.  The bright orange was easy to follow but it moved quickly, faster than we could bicycle.  This was also my second fox sighting, the first being along the same bike path by the river on the way home from school.  The dark of the night and the quietness of my bike lead to a very startled orange blur moving from the bath into the bushes.

The birds here are different than where I grew up.  I see cardinals every year, often in the winter and early spring.  I grew up around blue jays and blue birds which are equally vibrant but somehow the cardinal red seems more special and unique; it feels like something I am privileged to see. There are owls that frequent the banks of the river near our house now.  We hear them often at night with their characteristic hooting. The first time I heard them I didn't even notice as it seemed perfectly appropriate, like the right soundtrack cue was being played.  I eventually noticed I don't live in a TV show and that this was the first time I had ever heard a live owl.

We even have birds of prey.  Several times I've seen a hawk or falcon (I don't know which) flying through the neighborhood; there was even one on campus yesterday, hanging out on the lightpole.  Famously, there is a bald eagle that has taken up residence at a small lake a few blocks south of our house.  I haven't seen the bird myself but there is a regular small crowd at a nearby parking lot hoping to catch sight.

And of course there are rabbits.  Many rabbits.  My morning walk with the dogs is not complete without there multiple attempts to catch a rabbit.  Most of the time the are frustrated by the leash before they get close enough to claim the spoils of a hunt.  Occasionally they just aren't paying attention and a perfectly capture-able bunny escapes before they even know what happened.  Our dogs love the thrill of the chase.

Updated Home Temperature System

I've been having a problem with my home temperature system for a while and the issue really manifested itself over this winter.  The some of the sensors, some of the time seemed to head off the deep end and this winter, the outdoor sensor took a turn for the worse.  Here's what the system recorded on February 11, 2012.  Note the red outdoor trace headed off to Saudi Arabia.  Over the past week or two the trace has literally been off the charts reading over 140 'F all day long.

Based on the the little trouble-shooting I had done to try to fix this problem it seemed that the problem was rooted in the type of sensor I was using: semi-passive and analog.  The device is cheap and very easy to use but the output is weak and lacks the ability to consistently drive the relatively long cable runs (~50 feet) from sensor to processor.  Most of the sensors seem to work most of the time but I was having enough trouble that it seemed time to make a change.

My plan was simple: put an amplifier out by each sensor to provide enough drive to be immune from the unidentified craziness that seemed to come and go.  I found a candidate part and when it arrived this past Saturday I prototyped a new little sensor board Saturday evening and built and installed the rest on Sunday.  As you can see from the results below, things seem to be working much better.

Besides an increased reliability, the amplified sensors allow me to greatly increase the performance of the system overall.  The number of samples I average per log entry went from 35 to 1000 (take that central limit thereom!) and the time between log entries went from 3.5 minutes to 1 minute.  I could have easily pushed to system more in both direction but for now this seems more than adequate.

Before installing the sensors I tried to calibrate them with little success.  I placed a bad of crushed ice and water over the sensors with the hopes that all the sensors would reach the freezing point and I could compare their outputs.  After ten minutes of this it was obvious to me that this wasn't getting the sensors cold enough and so I settled for the next best thing.  Once the sensors reached room temperature again I simply compared their outputs and added an offset in the processing code to each one, bringing them all into rough agreement.  All the sensors now read the same temperature but there is no guarantee that this temperature is the correct one.  All six sensors are now consistent but not necessarily accurate in absolute terms.

I'm very happy with the results so far. The system is much less noisy and the higher update rate is nice; its like my temperature system is brand new again.

Nerd Details
The TMP36 is a nice little sensor but lacks drive; the output is high impedance and so it seems susceptible to static build-up and noise over these long cable runs I have.  Additionally, to measure multiple sensors on the Arduino, the high impedance forces long delays between read and multiple reads per sensors to get things accurate.  This limited the rate as which I could collect data and even then things didn't work so well, as can be seen above.

The op-amp I used is the MCP6002 which is a low-power, rail-to-rail op-amp. I did a quick characterization of the op-amp as a voltage follower and it followed the input 1:1 from 0.1 to 5V, more than enough range for the expected output of the TMP36 (and much better than the other op-amps I tried, see below).  Doing a little algebra revealed I could probably even amplify the signal a bit to push my nominal values a little bit out of the weeds (77'F is 0.75V).  Instead of configuring the op-amp as a follower I set it up as a non-inverting amplifier with a total gain of 2.82.  To prevent oscillation in driving my long twisted pairs and the capacitance they tend to create I used this table to make an informed guess and added a 470 ohm resistor in series with the output.  Finally, to make installing the sensor much easier, I used a three pin terminal block as the connector.

The changes to the Arduino code were trivial.  I got rid of the extra analogRead(), reduced the delay between reads down to 10ms (I tested at 5ms and it seemed to work just as well), changed the number of reads from 35 to 1000, changed a couple data types to accomodate the much larger values I'd be generating in the running total, and added a unique offset that is applied to each final averaged sensor value based on my quick and dirty "calibration" I had done at my desk.  Oh, and I divided the final converted temperature by the 2.82 gain factor the op-amp introduced.